1. Field of the Invention
The present invention relates to a driving apparatus and source driver thereof, and more particularly, to a driving apparatus and source driver thereof for driving a display panel.
2. Description of the Prior Art
Along with the advantages of thin appearance, low power consumption, and low radiation, liquid crystal displays (LCDs) have been widely applied in various electronic products for panel displaying. The operation of a liquid crystal display is featured by varying voltage drops between opposite sides of a liquid crystal layer for twisting the angles of the liquid crystal molecules in the liquid crystal layer so that the transparency of the liquid crystal layer can be controlled for illustrating images with the aid of the light source provided by a backlight module. In general, the liquid crystal display comprises a driving apparatus and a liquid crystal display panel. The driving apparatus is employed to provide a plurality of data driving signals to the liquid crystal display panel based on plural data signals, a horizontal synchronization signal, a vertical synchronization signal, a data enable signal and a clock signal.
FIG. 1 is a schematic diagram showing the structure of a prior-art liquid crystal display. As shown in FIG. 1, the liquid crystal display 100 comprises a driving apparatus 110 and a display panel 190. The driving apparatus 110 includes a timing controller 120 and a plurality of source drivers 150. The timing controller 120 has a first output port 121 and a second output port 122, i.e. based on two-port architecture. The first output port 121 is employed to output a first clock signal Sck1 and plural first data signals Sdata1. The second output port 122 is employed to output a second clock signal Sck2 and plural second data signals Sdata2. The first data signals Sdata1, the first clock signal Sck1, the second data signals Sdata2 and the second clock signal Sck2 are differential signals. Each source driver 150 includes an input port 155 and a driving output port 158. The input port 155 is electrically connected to the first output port 121 or the second output port 122. The driving output port 158 is electrically connected to the display panel 190. Regarding the structure of the driving apparatus 110, the input ports 155 of the source drivers X1˜X3 are electrically connected to the second output port 122 for receiving the second data signals Sdata2 and the second clock signal Sck2, and the input ports 155 of the source drivers X4˜X6 are electrically connected to the first output port 121 for receiving the first data signals Sdata1 and the first clock signal Sck1. It is noted that the number of the source drivers 150 disposed in the driving apparatus 110 are even.
In the structure of another prior-art liquid crystal display, the timing controller therein is based on single-port architecture and has only one output port for providing plural first data signals, plural second data signals and single clock signal. And each source driver receives all of the first data signals, the second data signals and the single clock signal. With the above in mind, it is obvious that the number of connection lines required for delivering data signals in two-port architecture is roughly half that of connection lines required for delivering data signals in single-port architecture. Consequently, the number of via holes required for each source driver in two-port architecture is significantly less than that of via holes required for each source driver in single-port architecture. In general, if the number of via holes is reduced, the signal integrity (SI) of differential signals is better and, in turn, the noise tolerance is higher, i.e. more suitable for achieving a high-frequency operation.
Besides, if the number of connection lines is reduced, the printed circuit board (PCB) which mounts the driving apparatus is able to spare more board area for accommodating more terminal resistors so as to further improve the signal integrity of differential signals received by each source driver. That is, although single-port architecture is suitable for disposing odd or even number of source drivers, most of the driving apparatus are still designed based on two-port architecture with the aim of enhancing operational performance. Furthermore, along with the development of the liquid crystal display having high resolution, the number of data driving lines connected to the display panel installed therein is increasing more and more, and the number of data driving lines connected to each source driver installed therein is also greater than ever. Following such development, the driving apparatus of the liquid crystal display is preferably required to accommodate odd number of source drivers. However, the prior-art driving apparatus based on two-port architecture is not suitable for accommodating odd number of source drivers, which means that the design of driving apparatus is hard to achieve both excellent operational performance and high application flexibility.